WATER CONDITIONERS FOR AGRICULTURAL FORMULATIONS

Abstract

Water conditioner compositions useful for agricultural formulations are disclosed. The compositions comprise ammonium sulfate, water, an optional antifreeze agent, and a blend comprising a C.sub.12-C.sub.14 fatty amine oxide and a C.sub.8-C.sub.10 fatty amine oxide. Agricultural formulations that comprise a weak acid-based herbicide and the water conditioner compositions are also described. The fatty amine oxides are compatible with the levels of ammonium sulfate needed for effective water conditioning. The formulated water conditioners resist separation for weeks at elevated and cold temperatures. Compared with water conditioners that contain alkylpolyglucosides, those formulated with the fatty amine oxide blends have reduced foaming problems and excellent wetting properties at relatively low surfactant concentration, thus demonstrating performance and cost advantages.

Claims

1. A water conditioner composition useful for agricultural formulations, comprising: (a) 30 to 50 wt. % of ammonium sulfate; and (b) 2 to 10 wt. % of a fatty amine oxide blend, the blend comprising: (b1) a C.sub.12-C.sub.14 fatty amine oxide; and (b2) a C.sub.8-C.sub.10 fatty amine oxide; and (c) water; wherein the weight % amounts are based on the amount of water conditioner composition.

2. The composition of claim 1 wherein the weight ratio of (b1) to (b2) is within the range of 10:1 to 1:10.

3. The composition of claim 2 wherein the weight ratio of (b1) to (b2) is within the range of 4:1 to 1:1.

4. The composition of claim 1 comprising 30 to 40 wt. % of ammonium sulfate.

5. The composition of claim 1 comprising 3 to 8 wt. % of the fatty amine oxide blend.

6. The composition of claim 1 wherein the C.sub.12-C.sub.14 fatty amine oxide comprises N,N-dimethyl-N-dodecylamine-N-oxide.

7. The composition of claim 1 wherein the C.sub.8-C.sub.10 fatty amine oxide comprises N,N-dimethyl-N-decylamine-N-oxide.

8. The composition of claim 1 further comprising 2 to 8 wt. %, based on the amount of water conditioner composition, of an antifreeze agent.

9. The composition of claim 8 wherein the antifreeze agent is a C.sub.2-C.sub.6 glycol.

10. The composition of claim 8 wherein the antifreeze agent is selected from the group consisting of glycerin, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, hexylene glycol, and mixtures thereof.

11. The composition of claim 1 comprising 25 to 68 wt. % of water.

12. The composition of claim 1 further comprising a secondary surfactant selected from the group consisting of nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and zwitterionic surfactants.

13. An agricultural formulation comprising: (a) a weak acid-based herbicide; and (b) the water conditioner composition of claim 1.

14. The composition of claim 13 wherein the herbicide is selected from the group consisting of glyphosates, glufosinates, phenoxycarboxylic acids, halobenzoic acids, pyrimidine carboxylic acids, pyrimidine carboxamides, pyridine carboxylic acids, pyridine carboxamides, sulfonylureas, and combinations thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

Water Conditioners

[0014] In some aspects, the invention relates to water conditioner compositions useful for agricultural formulations. The water conditioners comprise ammonium sulfate, water, an optional antifreeze agent, and a fatty amine oxide blend.

Ammonium Sulfate

[0015] Agricultural-grade ammonium sulfate is available from many suppliers. In general, the purity level is not crucial. Suitable water conditioner compositions will comprise 30 to 50 wt. %, or 30 to 40 wt. %, or 33 to 35 wt. % of ammonium sulfate, based on the amount of water conditioner composition.

Blend of Fatty Amine Oxides

[0016] The water conditioner compositions comprise 2 to 10 wt. %, or in some aspects 3 to 8 wt. %, based on the amount of water conditioner composition, of a fatty amine oxide blend. The blend comprises a C.sub.12-C.sub.14 fatty amine oxide and a C.sub.8-C.sub.10 fatty amine oxide. Suitable C.sub.12-C.sub.14 fatty amine oxides and C.sub.8-C.sub.10 fatty amine oxides are available commercially from Stepan Company as AMMONYX? LO and AMMONYX? DO, respectively. AMMONYX? LO is principally N,N-dimethyl-N-dodecylamine-N-oxide (a C.sub.12 fatty amine oxide, also known as lauramine oxide) with some N,N-dimethyl-N-tetradecylamine-N-oxide. AMMONYX? DO is principally N,N-dimethyl-N-decylamine-N-oxide (a C.sub.10 fatty amine oxide) with some N,N-dimethyl-N-octylamine-N-oxide.

[0017] The weight ratio of C.sub.12-C.sub.14 fatty amine oxide and a C.sub.8-C.sub.10 fatty amine oxide components in the blend can vary over a wide range. In some aspects, the C.sub.12-C.sub.14 fatty amine oxide is the major component, although we found that water conditioner compositions having only the C.sub.12-C.sub.14 fatty amine oxide present are considerably less effective providing storage stable water conditioners than conditioner compositions that include both C.sub.8-C.sub.10 and C.sub.12-C.sub.14 fatty amine oxides (see results in Tables 4-6 versus results in Table 7). Thus, in some aspects, the weight ratio of C.sub.12-C.sub.14 fatty amine oxide to C.sub.8-C.sub.10 fatty amine oxide is within the range of 10:1 to 1:1. In other aspects, the weight ratio of C.sub.12-C.sub.14 fatty amine oxide to C.sub.8-C.sub.10 fatty amine oxide is within the range of 4:1 to 1:1.

Water

[0018] The water conditioner compositions also contain water in an amount effective to solubilize the ammonium sulfate, antifreeze agent, fatty amine oxide blend, and any other components. Typically, the amount of water ranges from 25 to 68 wt. %, to 65 wt. %, or 45 to 60 wt. %, based on the amount of water conditioner composition.

Antifreeze Agent

[0019] Optionally, the water conditioner compositions comprise 2 to 8 wt. %, or 3 to 7 wt. %, or 4 to 6 wt. %, based on the amount of water conditioner composition, of an antifreeze agent. The antifreeze agent, when used, helps to minimize or prevent the formation of precipitates or crystals of ammonium sulfate and/or agricultural active (following combination of the water conditioner composition with the agricultural active). Suitable antifreeze agents are well known. In some aspects, the antifreeze agent is a C.sub.2-C.sub.6 glycol. Suitable antifreeze agents include, for example, glycerin, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, hexylene glycol, and the like, and mixtures thereof. Glycerin and propylene glycol are preferred.

Other Components

[0020] The water conditioners can include other components such as secondary surfactants (nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, zwitterionic surfactants), solvents, pH-adjusting agents, anti-foaming agents, chelating agents, or the like. In some aspects, the water conditioners consist of or consist essentially of ammonium sulfate, the fatty amine oxide blend and water. In other aspects, the water conditioners consist of or consist essentially of ammonium sulfate, the fatty amine oxide blend, an antifreeze agent, and water.

Agricultural Formulations

[0021] In some aspects, the invention includes agricultural formulations that comprise a weak acid-based herbicide and the water conditioner compositions described above. Suitable weak acid-based herbicides include compositions having weakly acidic protons. Many weak-acid herbicides are organic compounds that have carboxylic acid groups, phosphoric acid groups, or other relatively acidic protons. Classes of weak-acid herbicides include, for example, glyphosates, glufosinates, phenoxycarboxylic acids (e.g., 2,4-D, MCPA, MCPP, 2,4-DB, 2,4-DP), halobenzoic acids (e.g., dicamba), pyrimidine or pyridine carboxylic acids or carboxamides (e.g., aminocyclopyrachlor, picloram, imazethapyr, cyclopyralid, diflufenican), sulfonylureas (e.g., metsulfuron methyl), and the like, and combinations thereof.

[0022] The following examples merely illustrate the inventive subject matter. Many similar variations within the scope of the claims will immediately be apparent to those skilled in the art.

Compatibility of Ammonium Sulfate with Surfactants

[0023] For use in water conditioning, ammonium sulfate is generally formulated as an aqueous solution at about 34 wt. % of (NH.sub.4).sub.2SO.sub.4. A series of commercially available surfactants is combined at 5 or 10 wt. % surfactant with 34 wt. % ammonium sulfate to identify surfactants having adequate compatibility. Alkylpolyglucosides, which are compatible and commonly used in ammonium sulfate-based water conditioners, are not tested. In each case, ammonium sulfate is gradually added with good mixing to an aqueous solution of the surfactant. As shown in Table 1, relatively few classes of the screened surfactants are considered suitable for use based only on compatibility.

TABLE-US-00001 TABLE 1 Representative Surfactant Compatibility with 34 wt. % Ammonium Sulfate product.sup.1 class wt. % compatible? STEOL? CS270 sodium laureth 2 EO sulfate 5 no 10 no STEOL? C5460 sodium laureth 3.5 EO sulfate 5 no 10 no AMMONYX? LO N,N-dimethyl-N- 5 yes dodecylamine oxide 10 yes AMMONYX? DO N,N-dimethyl-N- 5 yes decylamine oxide 10 yes AMMONYX? MO N, N-dimethyl-N- 5 no tetradecylamine oxide 10 no STEPFAC? 8170 nonylphenol ethoxylate 5 no phosphate ester 10 no MAKON? DA-6 decyl alcohol 6 EO ethoxylate 5 no 10 no TOXIMUL? cocamine ethoxylate 5 no CA-7.5 10 no TOXIMUL? sorbitan trioleate ethoxylate 5 no SEE-340 10 no TOXIMUL? TA-8 tallowamine 8 EO ethoxylate 5 no TOXIMUL? TA-15 tallowamine 15 EO ethoxylate 5 no HALLCOMID? N,N-dimethylcapramide/N,N- 5 no M8-10 dimethylcaprylamide mixture BIO-TERGE? C.sub.14-C.sub.16 ?-olefin sulfonate 5 yes AS-40 10 yes AMMONYX? LO/ amine oxide mixture with 5 yes AMMONYX? DO/ propylene glycol PG blend MAKON? TD-50 tridecyl alcohol ethoxylate 10 no MAKON? TSP-60F tristyrylphenol ethoxylate 10 no .sup.1All surfactants are products of Stepan Company.

Shake Foam Test

[0024] A drawback of alkylpolyglucosides (APG) as surfactants for ammonium sulfate-based water conditioners is their tendency to produce stable foams. To compare the foaming properties of water conditioners made using amine oxide surfactants with those made using APG, the properties of both formulations are evaluated using the shake foam test.

[0025] Aqueous solutions containing 34 wt. % of ammonium sulfate and 56 wt. % of water are prepared. A comparative solution contains 10 wt. % of GLUCOPON? 420-UP alkylpolyglucoside surfactant (product of BASF). A test solution contains 3.5 wt. % of AMMONYX? LO surfactant, 1.5 wt. % of AMMONYX? DO surfactant, and 5.0 wt. % of semi-refined glycerin.

[0026] A 100-g portion of the solution is carefully transferred to a 500-mL graduated cylinder. The cylinder is stoppered and mechanically inverted ten times, then allowed to settle for 15 s. The initial foam height is recorded. After 5 min., foam height is recorded again. Two trials are performed for each mixture. Results appear in Table 2.

TABLE-US-00002 TABLE 2 Shake Foam Test Results Aqueous Ammonium Sulfate + Surfactant Initial Foam Foam Change Height Height at in foam Surfactant Trial (mL) 5 min. (mL) height (mL) Amine oxide blend 1 140 130 10 2 140 130 10 Alkylpolyglucoside 1 170 170 0 2 180 180 0

[0027] As shown in Table 2, the ammonium sulfate solution formulated with the amine oxide blend generates less foam volume than the solution formulated with the APG surfactant. Additionally, and the resulting foam begins to disintegrate more quickly with the amine oxide blend.

Draves Wetting Comparison

[0028] Draves wetting experiments are performed generally as described in ASTM D2281-68. Rapid wetting is considered to be less than about 40 seconds.

[0029] For the control experiment, the ammonium sulfate mixture with GLUCOPON? 420-UP prepared as previously described is diluted with water to 2.5 wt. % of its original concentration.

[0030] Various solutions containing 34 wt. % of ammonium sulfate, 56 wt. % of water, and 10 wt. % of a mixture of AMMONYX? LO, AMMONYX? DO, and glycerin as shown in Table 3 are prepared. Each of these solutions is diluted to 2.5 wt. % of its original concentration for use in the wetting test.

[0031] Similar solutions are prepared using propylene glycol instead of glycerin. These solutions generally give Draves wetting results in the 20-50 second range.

TABLE-US-00003 TABLE 3 Draves Wetting Comparison Component (wt. %) Control A B C D E F AMMONYX? LO 0 2.8 2.1 2.5 2.0 3.0 1.5 AMMONYX? DO 0 1.2 0.9 2.5 2.0 3.0 1.5 glycerin 0 6.0 5.0 5.0 6.0 4.0 5.0 GLUCOPON? 420-UP 10 0 0 0 0 0 0 Draves wetting, s 7.3 3.6 4.2 4.7 5.8 3.8 5.1

[0032] The results demonstrate excellent wetting properties for the tested and control formulations. However, wetting is as good or better in Formulations A-F with only 3-6 wt. % surfactant in the original mixture versus 10 wt. % APG in the control formulation, a potential cost savings when using the amine oxide blend. Because large amounts of surfactant are used in agricultural applications, small differences in the amount used can translate into a large cost differential.

Stability Testing

[0033] To evaluate the ability of amine oxide blends to impart storage stability to ammonium sulfate-based water conditioners, ammonium sulfate is combined at 34 wt. % with water and various combinations of AMMONYX? LO, AMMONYX? DO, and semi-refined glycerin. The mixtures are prepared and held for 14 days at 54? C., 25? C., 4? C., or ?15? C. Samples are inspected and rated for stability in comparison with a control sample containing 10 wt. % of AMMONYX? LO. The control sample is stable for 14 days at room temperature, but separation is apparent at the other tested temperatures. Ideally, no separation is observed at any of the temperatures.

[0034] As shown in Table 4, the 34 wt. % ammonium sulfate water conditioners containing combinations of AMMONYX? LO, AMMONYX? DO, and semi-refined glycerin are stable at all tested temperatures over a wide range of surfactant combinations and 3 to 6 wt. % amine oxide content. No separation is observed in any sample. In contrast, without the AMMONYX? DO also present (control sample), separation occurs when the samples are either heated or chilled.

[0035] Table 5 illustrates that similar excellent results can be achieved when 7 to 7.5 wt. % of propylene glycol is used instead of glycerin. Thus, at least in some aspects, a larger proportion of propylene glycol may be needed to get the same degree of compatibility observed with glycerin.

[0036] As shown in Table 6, other C.sub.2-C.sub.4 glycols (ethylene glycol, diethylene glycol) can be used alone or in combination with propylene glycol or glycerin to give stable ammonium sulfate-based water conditioners. In some samples, the most stressed conditions of ?15? C. promoted crystallization in some samples, but the overall results still exceed those seen with the control sample containing only AMMONYX? LO.

[0037] Table 7 summarizes the results of testing with other comparative formulations. Each of Comparative Examples 28-36 has 34 wt. % of aqueous ammonium sulfate and AMMONYX? LO as the only amine oxide. Although some samples were better than the control sample, the proportion of glycerin or propylene glycol can be varied without success in making a formulation that is stable at all tested temperatures. It is apparent that a blend of AMMONYX? LO with AMMONYX? DO is desirable for producing stable ammonium sulfate-based water conditioners.

TABLE-US-00004 TABLE 4 Stability Tests: Performance of Amine Oxide Blends with Glycerin Component (wt. %) control 1 2 3 4 5 6 7 8 9 ammonium sulfate 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 water 56.0 56.0 58.0 56.0 56.0 58.0 56.0 56.0 56.0 58.0 AMMONYX? LO 10.0 2.8 2.1 3.2 2.4 2.4 2.5 1.5 3.0 1.5 AMMONYX? DO 0 1.2 0.9 0.8 0.6 0.6 2.5 1.5 3.0 1.5 54? C. separates no separation 25? C. no separation no separation 4? C. separates no separation ?15? C. separates no separation

TABLE-US-00005 TABLE 5 Stability Tests: Performance of Amine Oxide Blends with Propylene Glycol Component (wt. %) control 10 11 12 13 14 15 16 17 18 ammonium sulfate 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 water 56.0 51.0 51.5 51.5 52.0 51.0 51.5 51.0 52.0 52.0 AMMONYX? LO 10.0 5.25 5.25 4.9 4.9 5.25 5.25 4.9 4.9 4.9 AMMONYX? DO 0 2.25 2.25 2.1 2.1 2.25 2.25 2.1 2.1 2.1 propylene glycol 0 7.5 7.0 7.5 7.0 7.5 7.0 8.0 7.0 7.0 54? C. separates no separation 25? C. no separation no separation 4? C. separates no separation ?15? C. separates no separation

TABLE-US-00006 TABLE 6 Stability Tests: Performance of Amine Oxide Blends with Glycols or Glycol Combinations Component (wt. %) control 19 20 21 22 23 24 25 26 27 ammonium 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 sulfate water 56.0 51.0 51.0 51.0 51.0 51.0 51.0 51.0 51.0 51.0 AMMONYX? LO 10.0 5.25 5.25 5.25 5.25 5.25 5.25 5.25 5.25 5.25 AMMONYX? DO 0 2.25 2.25 2.25 2.25 2.25 2.25 2.25 2.25 2.25 glycerin 0 7.5 0 0 3.75 0 0 1.88 0 0 ethylene glycol 0 0 7.5 0 0 3.75 0 0 1.88 0 diethylene glycol 0 0 0 7.5 0 0 3.75 0 0 1.88 propylene glycol 0 0 0 0 3.75 3.75 3.75 5.63 5.63 5.63 54? C. separates no separation 25? C. no separation no separation 4? C. separates no separation ?15? C. separates separates separates separates no no no no crystals crystals after thaw separation separation separation separation

TABLE-US-00007 TABLE 7 Stability Tests: Performance of AMMONYX? LO with Glycol Combinations (Comparative Examples) component (wt. %) control C28 C29 C30 C31 C32 C33 C34 C35 C36 ammonium 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 34.0 sulfate water 56.0 58.5 58.5 53.5 58.5 58.5 53.5 52.5 52.0 51.5 AMMONYX? 10.0 6.75 6.0 7.5 6.75 6.0 7.5 7.5 7.5 7.5 LO glycerin 0 0.75 1.5 5.0 0 0 0 0 0 0 propylene 0 0 0 0 0.75 1.5 5.0 6.0 6.5 7.0 glycol 54? C. separates equal equal worse equal equal no worse worse worse separation 25? C. no no no no no no no no no no separation separation separation separation separation separation separation separation separation separation 4? C. separates sl. better better equal sl. better better better worse worse worse ?15? C. separates equal equal equal sl. better better better worse worse worse No separation is the best result. When compared with a control sample that separates (i.e., at 54? C., 4? C., and ?15? C.), results are rated as equal, slightly better, better, or worse unless no separation is observed.

[0038] The preceding examples are meant only as illustrations; the following claims define the scope of the invention.